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Harmonic Vibrations of Nanosized Magnetoelectric Bodies with Coupled Surface and Interphase Effects: Mathematical Models and Finite Element Approaches
PublicationThe harmonic problems for piezomagnetoelectric nanosized bodies with taking into account the coupled damping and surface effects are considered on the base of the generalized Gurtin-Murdoch model. In the development of previous investigations, the coupled mechanical, electric and magnetic surface effects with surface inertial terms are introduced into the model. For a homogeneous model, the composite material is considered as homogeneous...
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Reinforcing and plasticizing effects of reclaimed rubber on the vulcanization and properties of natural rubber
PublicationThe production of high-added value reclaimed rubber (RR) is of great signifi-cance for the sustainability of rubber industries. To green recycle waste rub-bers and broaden the application of RR, a RR material with potentialreinforcing and plasticizing effects on nature rubber (NR) composites are pre-pared by a thermo-oxidative reclamation process. The reclamation degree ofRR is controlled by adjusting the content of soybean oil....
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Flexural behaviour of concrete slabs reinforced with FRP bars in experiments and according to aci ACI 440.1R guide
PublicationThe paper presents research conducted on two concrete slabs reinforced with the carbon composite bars and two other concrete slabs reinforced with basalt composite bars. The carbon bars were plain, while the basalt ones were ribbed. The slabs were experimentally investigated in the flexural state of effort with the concentrated forces applied. The results are compared with the analytical solution proposed in the guide ACI 440.1R-06...
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Water absorption and blistering of glass fibre-reinforced polymer marine laminates with nanoparticle-modified coatings
PublicationMacro and microstructural damage was studied in typical glass fibre-reinforced polymer laminates with two types of coating systems – (a) isophtalic gel coat: pure or mixed with SiO2 nanoparticles 5 wt% (5%N) or 10 wt% (10%N) and (b) a two-layer coating system: urethane-modified vinyl ester-based gel coat and additional polyester barrier coat layer. Accelerated tests were performed at 50C for 50 days for specimens with nanoparticle-modified...
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Material characterisation of biaxial glass-fibre non-crimp fabrics as a function of ply orientation, stitch pattern, stitch length and stitch tension
PublicationDue to their high density-specific stiffnesses and strength, fibre reinforced plastic (FRP) composites are particularly interesting for mobility and transport applications. Warp-knitted non-crimp fabrics (NCF) are one possible way to produce such FRP composites. They are advantageous because of their low production costs and the ability to tailor the properties of the textile to the reinforcement and drape requirements of the application....
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Stability analyses of a cylindrical steel silo with corrugated sheets and columns
PublicationW artykule przedstawiono wyniki obliczeń stateczności silosów z blachy falistej ze słupami. Wykonano analizy linowe i analizy nieliniowe stosując metody elementów skończonych. W obliczeniach uwzględniono model przestrzenny powłokowy oraz uproszczony model przestrzenny z blachy ortotropowej z belkami. Wyniki numeryczne porównano z Eurokodem.
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SILICA AEROGEL TOWARDS ANODES FOR LITHIUM-ION BATTERIES
PublicationAn increasing demand for electrochemical energy storage and conversion devices stimulates progress in research on electrode and electrolyte materials. In the field of electrodes materials, silicon is the one of the most promising anode materials for Li-ion batteries. However silicon has the drastic volume variation (around 3 times lower on extraction) during insertion and extraction of lithium ions. As an alternative, nanocomposites...
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Numerical simulations of novel GFRP sandwich footbridge
PublicationIn the following paper some aspects of numerical analysis and designing stages of a footbridge made of composite materials are elucidated. Because of the used materials the design process in this case is not ordinary and requires the development of concepts, material selections, identification of material properties, numerical simulations, strength calculations, serviceability and durability analyses. This contribution presents...
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Graphene Production and Biomedical Applications: A Review
PublicationGraphene is a two-dimensional nanomaterial composed of carbon atoms with sp2 hybrid orbitals. Both graphene and graphene-based composite have gained broad interest among researchers because of their outstanding physiochemical, mechanical, and biological properties. Graphene production techniques are divided into top-down and bottom-up synthesis methods, of which chemical vapor deposition (CVD) is the most popular. The biomedical...
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Nano Tin/Tin Oxide Attached onto Graphene Oxide Skeleton as a Fluorine Free Anode Material for Lithium-Ion Batteries
PublicationHerein, we show a composite formation method of tin/tin oxide nanoparticles with graphene oxide and CMC based on laser ablation technique as an electrode material for energy storage devices. The material exhibited a three-dimensional conducting graphene oxide network decorated with tin or tin oxide nanoparticles. The structure, homogeneous distribution of nanoparticles, and direct contact between inorganic and organic parts were...
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The cement-bone bond is weaker than cement-cement bond in cement-in-cement revision arthroplasty. A comparative biomechanical study
PublicationThis study compares the strength of the native bone-cement bond and the old-new cement bond under cyclic loading, using third generation cementing technique, rasping and contamination of the surface of the old cement with biological tissue. The possible advantages of additional drilling of the cement surface is also taken into account. Femoral heads from 21 patients who underwent a total hip arthroplasty performed for hip arthritis...
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Interval incidence graph coloring
PublicationIn this paper we introduce a concept of interval incidence coloring of graphs and survey its general properties including lower and upper bounds on the number of colors. Our main focus is to determine the exact value of the interval incidence coloring number χii for selected classes of graphs, i.e. paths, cycles, stars, wheels, fans, necklaces, complete graphs and complete k-partite graphs. We also study the complexity of the...
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Anna Danuta Dettlaff dr inż.
PeopleShe received her Master of Science degree in engineering with honours in 2013 at the Gdańsk University of Technology at the Department of Analytical Chemistry. In 2013-2017, she was a PhD student in the field of Chemical Technology at Faculty of Chemistry. Her doctoral dissertation was entitled “Nanocomposites based on conducting polymer and carbon materials for supercapacitor application”. In 2015, she was doing a three-month...
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Synthesis and photoelectrochemical behaviour of hydrogenated titania nanotubes modified with conducting polymer infiltrated by redox active network
PublicationIn this work, we show preparation of ordered inorganic-organic composite electrode material where hydrogenated titania nanotubes H-TiO2 with tubularly developed surface modified with poly(3,4-ethylenedioxythiophene) matrix permeated by Prussian Blue (PB) inorganic redox network in order to reach highly photoactive heterojunction. The polymer deposition was realized via two subsequent processes covering: i) potentiostatic polymerization...
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Cu-HKUST-1 and Hydroxyapatite–The Interface of Two Worlds toward the Design of Functional Materials Dedicated to Bone Tissue Regeneration
PublicationA novel composite based on biocompatible hydroxyapatite (HA) nanoparticles and Cu-HKUST-1 (Cu-HKUST-1@HA) has been prepared following a layer-by-layer strategy. Cu-HKUST-1 was carefully selected from a group of four Cu-based metal−organic frameworks as the material with the most promising antimicrobial activity. The formation of a colloidal Cu- HKUST-1 layer on HA nanoparticles was confirmed by various techniques, e.g., infrared...
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Implementation of the Concept of Flexicurity in the Selected Countries of Central Eastern Europe
PublicationThe CEE countries have to create their own flexicurity policies which would take into account the employment policy guidelines, cultural traditions and socio-economic development. The aim of this article is to examine and evaluate the implementation of the flexicurity concept on the basis of the adopted set of composite indicators. The study covers 9 countries of the CEE region, and the research period covers the years 2007 and 2013....
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Hybrid electrode materials for fast performance devices
PublicationEnergy storage devices such as Electrochemical Double Layer Capacitors and other types of the electrochemical capacitors require chemically stable, non-soluble, electrochemically active electrode materials compatible with appropriate electrolytes. Factors which determine their applicability are derived from so called electrochemical window of electroltes, nature of charge accumulation and their kinetics. On the other hand technological...
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Satellite pump and motor
PublicationThe article describe the design and operation of a prototype of satellite pump and a prototype of satellite motor. In both machines, the operating mechanism consists of a non-circular gear with external teeth (rotor), non-circular gear with internal teeth (curvature), and ten gear wheels which cooperate with the rotor and the curvature. The differences between the commutation unit in the pump and the commutation unit in the motor...
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Global edge alliances in graphs
PublicationIn the paper we introduce and study a new problem of finding a minimum global edge alliance in a graph which is related to the global defensive alliance (Haynes et al., 2013; Hedetniemi, 2004) and the global defensive set (Lewoń et al., 2016). We proved the NP-completeness of the global edge alliance problem for subcubic graphs and we constructed polynomial time algorithms for trees. We found the exact values of the size of the...
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Insights into Compatibilization of Poly(ε-caprolactone)-based Biocomposites with Diisocyanates as Modifiers of Cellulose Fillers
PublicationThis study aimed to analyze the impact of cellulose fillers’ modification with diisocyanates on the performance of composites based on the poly(ε-caprolactone) (PCL) matrix. Four most commonly used diisocyantes (isophorone, hexamethylene, toluene, and methylene diphenyl) were applied as modifiers of cellulose fillers (5 and 15 wt% per mass of filler). Modified fillers were introduced in the amount of 30 wt% into the PCL matrix....
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Investigation into the Effect of Spinel Pigments on the Photostability and Combustion Properties of Ethylene-Norbornene Copolymer
PublicationMulticolor ethylene-norbornene (EN) composites filled with three different spinel pigments (Cobalt Green-PG50, Zinc Iron Yellow-PY 119, Praseodym Yellow-PY159) were prepared by melt mixing and characterized in terms of their stability under destructive environmental conditions. The EN films were subjected to accelerated aging by ultraviolet (UV) photooxidation for 300 h, 600 h, or 900 h. The mechanical performance of the EN composites...
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Mater-Bi/Brewers’ Spent Grain Biocomposites—Novel Approach to Plant-Based Waste Filler Treatment by Highly Efficient Thermomechanical and Chemical Methods
PublicationThermoplastic starch (TPS) is a homogenous material prepared from native starch and water or other plasticizers subjected to mixing at a temperature exceeding starch gelatinization temperature. It shows major drawbacks like high moisture sensitivity, poor mechanical properties, and thermal stability. To overcome these drawbacks without significant cost increase, TPS could be blended with bio-based or biodegradable polymers and...
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Opitmalising Human Development Index with sensitivity analysis
PublicationResearch background: Composite indicators are commonly used not only to measure economic development, the standard of livin g, competitiveness, fairness, effectiveness but are also willingly implemented in to many different fields. How- ever, it seems that in most cases the variable weig hting procedure is avoided or erroneous since in most cases so-called “wights by belief” are...
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Non-Destructive Diagnostics of Concrete Beams Strengthened with Steel Plates Using Modal Analysis and Wavelet Transform
PublicationExternally bonded reinforcements are commonly and widely used in civil engineering objects made of concrete to increase the structure load capacity or to minimize the negative effects of long-term operation and possible defects. The quality of adhesive bonding between a strengthened structure and steel or composite elements is essential for effective reinforcement; therefore, there is a need for non-destructive diagnostics of adhesive...
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On the Correlation of Lignocellulosic Filler Composition with the Performance Properties of Poly(ε-Caprolactone) Based Biocomposites
PublicationIn this work, three types of agricultural waste: olive stones (OS), date seed (DS) and wheat bran (WB) were applied as potential lignocellulosic fillers in poly(ε-caprolactone) (PCL) based biocomposites. Differences in composites’ performance were related to the higher content of proteins, noted for WB comparing to other fillers applied, which enhanced plasticization of PCL matrix. The mechanical properties of biocomposites were...
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Aquatic biomass containing porous silica as an anode for lithium ion batteries
PublicationA composite electrode was manufactured by pyrolysis of Red Algae (Polysiphonia fucoides) covered by diatoms (Diatomophyceae). Electrodes were tested as a half cell with capacity of 500 mA h g−1 after 80 cycles. XPS analysis shows formation of lithium silicate under reduction of silica in an aprotic electrolyte containing LiPF6 salt.
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A novel hierarchically-porous diamondized polyacrylonitrile sponge-like electrodes for acetaminophen electrochemical detection
PublicationA novel composite electrode material consisting of tangled fibrous polyacrylonitrile-based hierarchically-struc- tured nanocomposites has been produced by wet-spinning, carbonized and decorated with a carbon nano- architecture by microwave plasma-enhanced chemical vapor deposition and investigated as a metal-free electrode for the enhanced electrochemical detection of acetaminophen. Surprisingly, the hierarchical fiber ar- chitecture...
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Ultrafast high-temperature sintering (UHS) of cerium oxide-based compound
PublicationUltrafast high-temperature sintering (UHS) is an innovative sintering technique that can densify ceramics in a few seconds, dramatically reducing the carbon footprint and firing costs. In this work, the feasibility of applying UHS in Gd-doped ceria (GDC) and GDC-Er-stabilized bismuth oxide (ESB) composite powders was investigated. At high UHS currents (22-24 A), a fully dense GDC sample with a large grain size was obtained. Nonetheless,...
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Synthesis, characterization, and application of 2D/2D TiO2-GO-ZnFe2O4 obtained by the fluorine-free lyophilization method for solar light-driven photocatalytic degradation of ibuprofen
PublicationIn this study, we report the potential of 2D/2D TiO2- GO-ZnFe2O4 photocatalyst obtained using the fluorine-free lyophilization technique for the degradation of ibuprofen belonging to the group of active pharmaceutical ingredients (API). The improved ibuprofen degradation under simulated solar light was achieved in the presence of a composite of 2D TiO2 combined with GO and embedded ZnFe2O4, which additionally provides superparamagnetic...
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Synergistic effect of multi walled carbon nanotubes and reduced graphene oxides in natural rubber for sensing application
PublicationUtilizing the electrical properties of polymer nanocomposites is an important strategy to develop high performance solvent sensors. Here we report the synergistic effect of multi walled carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO) in regulating the sensitivity of the naturally occurring elastomer, natural rubber (NR). Composites were fabricated by dispersing CNTs alone and together with exfoliated RGO sheets (thermally...
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Analysis of the process of water entry of an amphibious vehicle
PublicationThe paper presents a method of computational and experimental analysis of the process of water entry of an amphibious vehicle. The computational method is based on the Reynolds Averaged Navier-Stokes Equations (RANSE) solver and the xperiment was carried out in the towing tank at Ship Design and Research Centre S.A. with the use of a scale model. The analysis was focused on the safety of water entry, i.e. the maximum pitch and...
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Karol Flisikowski dr inż.
PeopleKarol Flisikowski works as Associate Professor at the Department of Statistics and Econometrics, Faculty of Management and Economics, Gdansk University of Technology. He is responsible for teaching descriptive and mathematical statistics (in Polish and English), as well as scientific research in the field of social statistics. He has been a participant in many national and international conferences, where he has presented the results...
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The Influence of Workpiece Hardness on Plate Temperature during One Side Lapping
PublicationLapping leads to a surface with low roughness and high precision. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. The goal was to determine the correlation between the basic lapping conditions and wheel temperature. In work Bulsara et al. authors developed model to estimate the maximum and average temperature...
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Recent Advances in Development of Waste-Based Polymer Materials: A Review
PublicationLimited petroleum sources, suitable law regulations, and higher awareness within society has caused sustainable development of manufacturing and recycling of polymer blends and composites to be gaining increasing attention. This work aims to report recent advances in the manufacturing of environmentally friendly and low-cost polymer materials based on post-production and postconsumer wastes. Sustainable development of three groups...
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Ireneusz Kreja dr hab. inż.
PeopleGraduated from the mathematical class at the Nicolaus Copernicus High School in Gdańsk (1974). Master of Sciences in Civil Engineering after studies at Gdansk University of Technology (GUT), Poland (1974-1979). Since 1979 became an employee of the GUT. In 1989 earned a Ph.D. degree in Civil Engineering (with grade "Summa cum Laude") from the GUT. In 2008 obtained a D. Sc. (Habilitation) degree in Civil Engineering (with grade...
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Cost-Efficient Design Methodology for Compact Rat-Race Couplers
PublicationIn this article, a reliable and low-cost design methodology for simulation-driven optimization of miniaturized rat-race couplers (RRCs) is presented. We exploit a two-stage design approach, where a composite structure (a basic building block of the RRC structure) is first optimized using a pattern search algorithm, and, subsequently, the entire coupler is tuned by means of surrogate-based optimization (SBO) procedure. SBO is executed...
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Materiały stosowane do wytwarzania implantów kości
PublicationMateriały stosowane do wytwarzania implantów kostnych muszą być biokompatybilne, nietoksyczne, bioaktywne oraz wykazywać odpowiednie właściwości mechaniczne, takie jak wytrzymałość na ściskanie, na zginanie oraz sztywność i twardość. Gama stosowanych materiałów jest bardzo szeroka, obejmuje metale, polimery, ceramikę oraz ich kompozyty. Każdy z tych materiałów ma swoje mocne i słabe strony. Praca stanowi przegląd materiałów stosowanych...
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Sensitivity analysis as a tool to optimise Human Development Index
PublicationResearch background: Composite indicators are commonly used as an approximation tool to measure economic development, the standard of living, competitiveness, fairness, effectiveness, and many others being willingly implemented into many different research disciplines. However, it seems that in most cases, the variable weighting procedure is avoided or erroneous since, in most cases, the so-called...
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublicationThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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Electrochemical investigations of conductive coatings applied as anodes in cathodic protection of reinforced concrete
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A novel stiffener skeleton strategy in catalytic carbonization system with enhanced carbon layer structure and improved fire retardancy
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation...
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublicationEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublicationEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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Mechanical and microstructural properties of cement pastes containing carbon nanotubes and carbon nanotube-silica core-shell structures, exposed to elevated temperature
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Dielectric properties of modified graphene oxide filled polyurethane nanocomposites and its correlation with rheology
PublicationThis study aims at investigating the dynamic mechanical, dielectric and rheological properties of reinforced polyurethane (PU) nanocomposites containing hydrophilic graphene oxide (GO) and/or hydrophobic modified graphene oxide (mGO) sheets. The organic modification of GO was performed with 4,4′-methylenebis (phenyl isocyanate) (MDI) and the samples were prepared by solvent mixing. We found that addition of mGO provides a more...
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Effect of starch fillers on the dynamic mechanical properties of rubber biocomposite materials
PublicationIn the paper the results of dynamic mechanical study of the biocomposites containing one of two types of (potato or corn) strach used as fillers in different amount were discussed. The composites were obtained from rubbery mixture containing natural rubber (NR) as a main component. Thermomechanical analyses (by DMA) showed that the used quantity of strach fillers only slightly influence on the glass transition temperature of vulcanizates.
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Physical and mechanical properties of rigid polyurethane faoms modified with selected flame retardants or layered silicates
PublicationW pracy przedstawiono charakterystykę pianek poliuretanowych zawierających klasyczne środki uniepalniające oraz nanonapełniacze z grupy glinokrzemianów warstwowych. Zbadano wpływ zarówno nanonapełniaczy na bazie naturalnego montmorylonitu, jak i modyfikowanych glinokrzemianów. Uzyskane spienione poliuretanowe o zmniejszonej palności charakteryzowano z wykorzystaniem różnych technik badawczych, między innymi wykonano badania DMA,...
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Experiments and calibration of a bond-slip relation and efficiency factors for textile reinforcement in concrete
PublicationTextile reinforcement yarns consist of many filaments, which can slip relative each other. At modelling of the global structural behaviour, interfilament slip in the yarns, and slip between the yarns and the concrete can be considered by efficiency factors for the stiffness and strength of the yarns, and by applying a bond-slip relation between yarns and concrete. In this work, an effective and robust method for calibration of...
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Hydrogen Bonds in Blends of Poly(N-isopropylacrylamide), Poly(N-ethylacrylamide) Homopolymers, and Carboxymethyl Cellulose
PublicationRecently, it was reported that the physical crosslinking exhibited by some biopolymers could provide multiple benefits to biomedical applications. In particular, grafting thermoresponsive polymers onto biopolymers may enhance the degradability or offer other features, as thermothickening behavior. Thus, different interactions will affect the different hydrogen bonds and interactions from the physical crosslinking of carboxymethyl...